Understanding how frogs and other amphibians move through their environment is crucial. That’s why researchers and environmentalists do it for effective conservation efforts.
Movement is an important part of a species’ interaction with its surroundings. Any disruptions in amphibian habitats can impact their populations.
There was a need to address the lack of data on the movement behavior of a nocturnal tree frog. It’s also known as Burmeister’s leaf frog (Phyllomedusa burmeisteri).
So, a team from Brazil and Germany conducted a study within the Reserva Ecologica Michelin in Brazil’s Bahia region. The findings, published in Scientific Reports, provide insights into the movement patterns of these frogs and their relationship with the environment.
Burmeister’s leaf frogs
These Burmeister’s leaf frogs undergo a transformation from tadpoles in ponds to land dwellers when they’re more mature.
Unlike leaping or jumping, they move using their legs, often clinging to surfaces like tree branches.
Factors that affect their movement include the availability of resources and the landscape structure. Understanding their movement sheds light on various aspects of their lives. We’ll know their habitat range, population densities, migration patterns, and breeding locations.
Now, in the study, the researchers wanted to estimate how far the frogs travelled within one day or four. This was done to get a good grasp of their movement patterns.
Moreover, the researchers tried to identify any connections between a frog’s weight and its movement. They want to compare the patterns of the frogs from forest ponds with ones from ponds outside the forest.
This study was done by attaching a backpack-like device with a spool-and-line mechanism to each frog. The spool was wound with approximately 250 meters of line. Not to worry about being unethical, the device must weigh less than 10% of the frog’s body weight. You can see the device here.
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Tracking the froggies
Over four days, the researchers monitored each frog by following the line.
They regularly checked for injuries, and replaced the spools as needed to ensure the line did not run out. The researchers also recorded the distances covered, the maximum heights reached, and the frogs’ behaviors during their observations.
The team observed that these tracking devices did not hinder the frogs’ natural activities. All of them could walk, climb trees, and move through water without difficulty.
Now, the mean total movement distances showed no significant difference between forest and open areas. However, forest-dwelling frogs reached greater heights. Furthermore, those in open areas took slightly more steps on average.
All the study subjects displayed random variations in horizontal and vertical movements. Similar fluctuations also happened in travel during directional changes and in their daily activity patterns.
Frogs from open areas showed less movement to the east but more frequently moved to the north, west, and south. That’s consistent with the pond locations in the west.
In contrast, frogs from the forest where the ponds are in the southern parts moved less frequently to the north. Instead, they traveled more to the west, south, and east.
The researchers found a positive relationship between a frog’s weight and traveling distance. The heaviest frog (40.77 g) moved the greatest distance (4,824 cm). Another frog approximately half its size (20.5 g) covered nearly the same distance (4,700 cm).
What’s so significant about frogs’ movement?
According to the researchers, this research adds more knowledge to the existing work on movement behavior of frogs in Brazil.
This discovery includes details of turning angles. So, it also shows that P. burmeisteri may move more slowly and carefully than other tree frogs. However, they cover comparable daily distances.
“Even though this species is mostly found in tree branches, it also uses microhabitats such as low vegetation (herbs and logs), as well as medium and higher vegetation and aquatic environments,” the paper states.
The use of various environments might be significant to this species for reproduction reasons.
Per the researchers, the frogs of open areas liked lower vegetation, and were frequently recorded at lower heights. They mostly ignored large trees and medium vegetation.
“This can perhaps be explained by the fact that it was not their breeding period. And high exposure is one of males’ behavioral strategies to win sexual partners.”
Future strategies
According to the researchers, more studies on these frogs may be done in the same two locations.
So, the focus can point to identifying differences in each location’s food supply, if there’s any. Because up to this point, there’s no literature on the topic.
Future studies could also focus more on the frogs’ vertical movements compared to height and number of trees in each area.
Better now than later
The work of this research team is an important initial effort. And in the future, they plan to continue studying the movement of this species for longer periods, in different seasons.
Now, the frogs themselves are not too threatened: the conservation status of P. burmeisteri is still Least Concern.
But it’s precisely because of that reason that such studies are better done now. So, we can prepare ourselves for future conservation strategies. Besides, it’s better to prevent rather than reverse.
Otherwise, it may take a whole community to save just one species—like the case of the Togo slippery frog.
The species was once thought extinct. It experienced a dramatic population decline due to human activities like hunting, fishing, and habitat destruction.
In 2007, in western Togo and southern Ghana, Caleb Ofori-Boateng spotted one after the last recorded sighting in 1980. Ofori-Boateng is Ghana’s first trained herpetologist, and he then found the frog again in 2013 in Ghana.
The Togo slippery frog is famous for its whistling call. It now ranks 18th on the list of 100 highly unique and endangered amphibians.
Recent assessments estimated about 249 frogs across Togo and Ghana. All Ghanaian frogs living in the Togo-Volta highlands.
“It’s totally unique, and there’s no other frog left on the planet like it,” Ofori-Boateng said. To put it simply, the frog captivated the herpetologist, and he was moved to act even before meeting one.
Helping the species
In 2006, Ofori-Boateng founded Herp-Ghana, West Africa’s first amphibian-focused conservation nonprofit. It addresses challenges faced by species like the Togo slippery frog.
Within a decade of community efforts and education, the nonprofit curbed illegal activities like logging and hunting.
Before, the locals believed the frogs had the magical power to change the sex of whoever they jumped onto. Others consumed frogs as a delicacy. Then, the communities were heavily reliant on logging for their income and couldn’t understand why forest conservation was important.
But over time, Ofori-Boateng began to receive constant support.
In 2018, Herp-Ghana created the 864-acre Onepone Endangered Species Refuge. It actively involved the community. According to Ofori-Boateng, recent estimates show that the frog population has more than doubled since its last estimates in 2013.
The new reserve is welcomed by the community, underscoring the positive outcomes of Ofori-Boateng’s innovative approach, including “conservation evangelism.”
Ofori-Boateng also gained community support through emphasizing the potential value of frogs socioeconomically.
Therefore, Onepone Endangered Species Refuge has expanded 12,000 acres. Since finding an additional 350 Togo slippery frogs outside the confines of Onepone, Ofori-Boateng took it further.
He and his team have appied to the local municipal government to create an additional area that will span 2,470 acres. This will protect the new cluster of frogs and 12 other critically endangered, vulnerable and near-threatened species.
Herp-Ghana has successfully combined nature preservation with community welfare by collaborating with local stakeholders.
Ofori-Boateng’s reserve and community efforts may lead to putting the species from being critically endangered to endangered.
Cherishing what we have now
Now, Ofori-Boateng’s case results in a heartwarming and relatively successful outcome. Some other species haven’t been as lucky.
And that’s why it’s important to do preventions now. They can be in the form of tracking common frogs like the researchers or rallying communities to take necessary actions.
But one thing to remember is that it’s good to remain optimistic. Even Ofori-Boateng believes that conservation crisis is reversible.
“Reversing the biodiversity crisis is very possible—the solutions are not far-fetched. I am very positive that things will only get better,” he said.
Sources:
https://phys.org/news/2023-10-movement-patterns-leaf-frogs-brazil.html
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